Histone methyltransferase G9a is responsible for H3K9 di-methylation (H3K9me2), an epigenetic mark for gene repression. However, the roles of G9a and G9a-mediated H3K9me2 in adipogenesis have not been reported. We report recently that G9a represses PPARgamma expression and adipogenesis. G9a regulates both positive and negative master regulators of adipogenesis: G9a represses PPARgamma expression dependent on its H3K9 methyltransferase activity while promotes Wnt expression independent of its enzymatic activity (EMBO J 2013). Together with our previous report that H3K4 methylation regulator PTIP is required for PPARgamma and C/EBPa expression and adipogenesis, these findings provide an initial view of epigenetic regulation of adipogenesis, and suggest that histone methylations control expression of positive and negative master regulators of adipogenesis.